A pinion shift device for a starter generally comprises a unidirectional clutch having a clutch body and a clutch sleeve which is integral with the clutch body and slidably fitted over an output shaft of an electric motor, and a shift lever which is swingably supported at its intermediate portion and has a two-forked portion. The shift lever pushes the clutch sleeve to move in the axial direction so that the pinion is brought into mesh with a ring gear of an engine.
The prior art relating to interconnection between the two-forked portion of the shift lever and the clutch sleeve in such a pinion shift device is known as follows. JP, B, 63-44945 discloses the arrangement that a shift flange is provided on the clutch sleeve while forming an axial gap between the clutch body and the shift flange, and the two-forked portion of the shift lever is directly loosely fitted in the axial gap. JP, A, 63-129165 discloses the arrangement that a semicircular ring-shaped shift plate is pivotably coupled to an end of the two-forked portion of the shift lever and the shift plate is loosely fitted in the axial gap between the clutch body and the shift flange. JP, B, 62-56350 discloses the arrangement that a circular ring-shaped shift plate is pivotably coupled to the end of the two-forked portion of the shift lever and the shift plate is inserted in the axial gap between the clutch body and the shift flange. In the case of using the shift plate, a pin or a screw is used as means for pivotably coupling the shift plate to the shift lever. Additionally, in the device disclosed in the above-cited JP, B, 62-56350, the shift lever and the shift plate are both molded using resin.
Further, relating to the prior art in which the twoforked portion of the shift lever is directly loosely fitted in the axial gap between the clutch body and the shift flange, JP, A, 63-215873, JP, A, 63-21362, etc. disclose the arrangement that the shift lever is molded using resin and a recessed groove for accumulating grease therein is formed in a slide contact portion of the resin-made shift lever with the clutch sleeve.